Diskeeper is unable to completely optimize the specified drive as there is a rather large green/white striped area known as reserved system space. This is free area however Diskeeper will not use this area for defragmentation.
To utilize this "wasted" space, the hard drive space needs to be used to capacity. A script was found to create files and folder structures that would impede into the reserved system space. Once this space is breeched, the OS will reduce the size of the reserved system space. Continue to use the script through to the desired size. Then delete the files/folders and run defrag.
Here is a script, save as BAT or CMD and execute.
REM Create folder and change to it. MD 10KF CD 10KF REM Create 10000 Folders FOR /L %f in (1,1,10000) do md %f CD.. REM Create folder and change to it. MD 50KFILES CD 50KFILES REM Create 50000 files with Hey as contents FOR /L %f in (1,1,50000) do echo Hey > %f REM http://www.tweakxp.com/article37012.aspx